The present invention relates generally to electrical switches and, more particularly, to an electrical trigger switch with both mechanical and electrical safety features. Many types of equipment include a manual control (such as a "joy stick") for an operator to signal the equipment to operate in a particular manner. Such controls often include an electrical trigger switch. When depressed, the trigger switch allows current to flow from one main lead to another and thus activate machinery to perform in a particular manner.
In many applications, it is particularly important that the trigger not be depressed accidentally. In such cases, the trigger switch may be fitted with a stiff spring to resist low pressure accidentally applied to the trigger. In other applications, including, for example, aircraft, trigger switches may also include a finger guard. The guard may pivot away from the trigger (in an "armed" position), to allow the trigger to be depressed. Alternatively, the guard may pivot to a position substantially adjacent the trigger (in a "guard" position), to physically block anything from coming in contact with the trigger, thus preventing the trigger from being accidentally depressed and activating the machinery.
Unfortunately, mechanical trigger guards may not always achieve their purpose. In particular, instances of guard failure may occur where the machinery and controls are subjected to physical punishment or other harsh environments. Also, the guard may fail a due to age or improper assembly.
For example, the trigger guard may be may break off about the pivot point and thereafter provide no protective structure for the trigger. Also, the guard may accidentally be pivoted to a position intermediate to the armed and guard positions. In such a case, where the guard is not closed all the way, a finger may be inserted in between the guard and the trigger, allowing the trigger to be depressed, even though the operator had previously intended to pivot the guard to the "guard" position.